Motion Flashcards
What is a frame of reference?
A system of objects that are at rest with respect to each other. Motion is determined by the observer’s position within or outside the system.
What is the origin?
A determined position from which other positions are measured.
What is a vector?
A vector represents a measurement that has both magnitude and direction. Vectors are arrows with the length representing magnitude and the tip representing direction.
What is a scalar?
A measurement that only has magnitude.
What is distance?
The separation between two points. Unit for distance is meter. Distance is a scalar.
What is displacement?
Measurement of the change of position. Unit for displacement is meter. Displacement is a vector.
What is position?
The distance of a point measured from the origin. Unit for position is meter. Position is a vector.
What is average speed?
Speed measures the distance travel in a given time. Unit for speed is m/s. Speed is a scalar.
What is velocity?
Velocity measures the change in position in a given time. Unit for velocity is m/s. Velocity is a vector.
What is acceleration?
Acceleration measures the change in velocity in a given time. Unit for acceleration is ㎨ Acceleration can occur if the speed changes, the direction of motion changes or both change.
What is a resultant vector?
Vectors add head to tail in any order. The resultant vector is drawn from the tail of the first vector to the head of the last.
If an object starts from rest, what information does that statement provide?
The starting velocity is 0 m/s.
If an object comes to a stop, what information does that statement provide?
The final velocity is 0 m/s.
If an object is in free fall, what information does that statement provide?
Gravity is the only force acting on the object. Acceleration is 9.8 ㎨.
If an object is moving with constant velocity, what information does that statement provide?
The acceleration of the object is 0 ㎨.
On a position-time graph, the what are the x-axis and y-axis labels?
The x-axis is time in seconds, and the y-axis is position in meters.
On a position-time graph, what variable does the slope determine?
The slope of a position-time graph is the object’s velocity.
On a position-time graph, if the slope is positive, what does that convey about the object’s motion?
The object is moving in the positive direction.
On a position-time graph, if the slope is a horizontal line, what does that convey about the object’s motion?
The object is not moving. Its velocity is 0 m/s.
On a position-time graph, if the slope is negative, what does that convey about the object’s motion?
The object is moving in the negative direction.
On a velocity-time graph, what are the variables on the x-axis and y-axis?
The x-axis is time in seconds, and the y-axis is velocity in m/s.
On a velocity-time graph, what variable does the slope measure?
The slope of a velocity-time graph is the object’s acceleration.
On a velocity-time graph, what does a positive slope indicate?
The object is accelerating.
On a velocity-time graph, what does a horizontal line indicate?
The object is moving with a constant velocity and is not accelerating.
On a velocity-time graph, what does a negative slope indicate?
The object is decelerating.
When graphing motion using a motion detector, how is direction indicated?
The motion detector is at the origin. Motion away from the detector is positive (increasing position), and motion towards the detector is negative (decreasing position).
What is the unit for acceleration?
meters per second squared (㎨)
What is the unit for velocity?
meters per second (m/s)
What is the unit for time?
seconds (s)
What is the unit for position?
meters (m)
What is the unit for displacement?
meters (m)
What variable is found by calculating the area under a velocity-time graph?
displacement
What variable is found by calculating the area under an acceleration-time graph?
velocity
What is deceleration?
Acceleration in a direction opposite velocity
A student walks 15 m to the east, then turns and walks 25 m to the west. What distance did the student walk? What is the student’s displacement?
The distance is 40 m.
The displacement is 10 m west.
